Of all the songs on Sturgill Simpson’s second album Metamodern Sounds in Country Music, none has been as analyzed as the record’s opening track, “Turtles All the Way Down.” A philosophical journey through religion, the universe and, especially, the mind, the song features references to marijuana, LSD and other psychedelics.

The Kentucky singer performed “Turtles All the Way Down” last night on The Tonight Show Starring Jimmy Fallon, making his debut on the venerable NBC talk show. With his band mostly shrouded in shadow — including mesmerizing guitarist Laur Joamets, from Estonia — Simpson rolled through the song with a low-key yet powerful delivery, strategically elevating his voice for effect. Watch the video above.

“The turtle myth is kind of a comedic expression in metaphysics now. It represents a much grander idea of what is known as the Unmoved Mover, or this one central divine source of all complex consciousness in the universe,” Simpson explained. “And according to the theory — and I say theory because I don’t ever want to say I agree with it — but it is still a beautiful idea that everything is being emitted from one point and that we’re all this universal shared consciousness.”

The deep-thinking Simpson, who was named Emerging Artist of the Year at the recent Americana Honors & Awards, performed at Nashville’s Ryman Auditorium this past weekend, opening the final night of Jason Isbell’s three-night stand at the storied venue. Ironically, back in May, Simpson told Rolling Stone Country that he still hadn’t heard Isbell’s acclaimed album Southeastern for fear it would too greatly influence him.

“I know if I listen to it, I’ll fall in love with it. And then I’ll put out [an album], and ‘Oh, well, here’s Sturgill’s Southeastern,” he said. “So you have to intentionally really be careful.”

Simpson will perform on Halloween at the Voodoo Festival in New Orleans, before hitting the road for a four-month tour that hits such major markets as New York, Philadelphia, Boston and Washington, D.C.